I found this little blurb in the Houston Chronicle in the “Earthweek” section:

“Musical talent in humans and other creatures appears related to needs to move as synchronized groups in avoiding danger, one researcher says. Matz Larsson, senior physician at Sweden’s Örebro University Hospital says musical traits have been engendered by the need for some species to coordinate sounds that briefly prevent them from hearing predators and other dangers. Such behavior favoring evolutionary success is typically rewarded with the release of the ‘feel good’ chemical dopamine in the brain”.